Reducing the level of bacteria and viruses in aquaculture

Abstract

A method of reducing the level of bacteria and viruses in a volume of water during aquaculture comprises:—(a) providing the volume of water to be stocked with farmed aquatic organisms or eggs thereof; (b) prior to the stocking, introducing into the water an aqueous solution of glutaraldehyde in an amount such as to provide in the water from 0.1 to 2 ppm of glutaraldehyde; (c) stocking the water with the farmed aquatic organisms or eggs thereof at a time when the concentration of glutaraldehyde is 0.1 to 2 ppm. (d) allowing the farmed aquatic organisms or eggs thereof to grow; and (e) optionally during a period of the growth, introducing into the water at least one further portion of an aqueous solution of glutaraldehyde in an amount such as to maintain the concentration of the glutaraldehyde at 0.1 to 2 ppm.

1. A method of reducing the level of bacteria of the species Vibrio and viruses selected from the group consisting of White Spot Syndrome Bacilovirus (WSBV) complex, Yellowthread Virus, Taura Syndrome Virus and combinations thereof in a volume of water during aquaculture, which method comprises:
 (a) providing the volume of water to be stocked with farmed crustacea or eggs thereof; 
 (b) prior to the stocking, introducing into the water an aqueous solution of glutaraldehyde in an amount such as to provide in the water from 0.5 to 2 ppm of glutaraldehyde; 
 (c) stocking the water with the farmed crustacea or eggs thereof at a time when the concentration of glutaraldehyde is 0.5 to 2 ppm; 
 (d) allowing the farmed crustacea or eggs thereof to grow; and 
 (e) optionally during a period of the growth, introducing into the water at least one further portion of an aqueous solution of glutaraldehyde in an amount such as to maintain the concentration of the glutaraldehyde at 0.5 to 2 ppm. 
 
   
   
     2. The method according to  claim 1 , wherein the concentration of glutaraldehyde in each of steps (b), (c) and (e) is within the range 0.5 to 1.5 ppm. 
   
   
     3. The method according to  claim 1 , wherein the bacteria of the species  Vibrio  are selected from the group consisting of  Vibrio parahaemolyticus, Vibrio harveyi  and combinations thereof. 
   
   
     4. The method according to  claim 1 , wherein the viruses are WSBV complexes selected from the group consisting of HABV; RV-JP; SEMBV and combinations thereof. 
   
   
     5. The method according to  claim 1 , wherein the crustacea or eggs thereof are shrimps, prawns or eggs thereof. 
   
   
     6. A The method according to  claim 1 , wherein the crustacea are selected from the group consisting of  Litopenaeus vannamex, Litopenaeus setiferus, Litopenaeus stylirostris, Litopenaeus aztecus, Litopenaeus chinensis, Litopenaeus duorarurn, Penaeus monodo, Panaeus vannamei  and combinations thereof. 
   
   
     7. The method according to  claim 1 , which includes the step (e). 
   
   
     8. The method according to  claim 7 , wherein at least two portions of the glutaraldehyde are introduced into the water, with an interval of from 5 to 10 days between respective additions thereof. 
   
   
     9. The method according to  claim 1 , which includes, in addition to step (e), a further final period of growth during which no further glutaraldehyde is added. 
   
   
     10. The method according to  claim 9 , wherein the said further final period is at least thirty days. 
   
   
     11. The method according to  claim 1 , which is carried out using a sealed aerated pond. 
   
   
     12. A The method according to  claim 1 , which is carried out in a marine environment.